Sometimes the beam of the fatal focus gets stuck in a firing animation while it's not actually firing (no enemies are within range), so the beam is constantly visible on screen. Does not appear to affect the actual functionality of the turret
Step by step of the bug
Step 1
Build Fatal Focus
Step 2
Enemy(s) enter range of Fatal Focus
Step 3
Fatal Focus activates
Step 4
No more enemies are within range of Fatal Focus
Step 5
Fatal Focus beam stays on-screen locked in place, while the turret idle animation plays
Sometimes the beam of the fatal focus gets stuck in a firing animation while it's not actually firing (no enemies are within range), so the beam is constantly visible on screen. Does not appear to affect the actual functionality of the turret